horiba APNA-370, Operation Manual, Page: 40 / 113

4 CALIBRATION
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4.4.3 Span calibration
1.
On the CAL. screen, check that the proper measurement line is selected.
If necessary, press the displayed MODE setting on the CAL. screen to display the
MODE screen, and then change the setting and press the [SET] key on the MODE
screen.
When using the calibration gas line: Select [SPAN].
When using the measured gas line: Select [MEAS.].
Fig. 38 MODE screen
2. When using the measured gas line, supply the span gas from the sample gas inlet.
3.
Wait for the readouts to be stabilized and then press the [SPAN] key on the CAL.
screen. The span calibration message will be displayed.
Fig. 39 Span calibration message
Note
The [SPAN SET] key on the CAL. screen is valid only when MODE is set to MEAS. or SPAN.
4.
Press the [YES] button. The span calibration will be started. After the calibration is
completed, the span calibration coefficient will be updated and the CAL. screen will
be displayed again.
Tip
To return the CAL. screen without executing span calibration, press the [NO] button of the span
calibration message.
Note
If the result of the NO or NOx span calibration deviates from the allowable range of span calibration
(0.5 to 2.0), the SPAN (span calibration) alarm occurs (see “8.2 Alarm List” (page 83)) and the span
calibration coefficient is not updated. In this case, the span calibration coefficient displayed on the
CAL. screen blinks. And if the standard output terminal block is provided, the alarm contact signal is
outputted. See the rear panel signal table at the end of this document.